Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
1. Cellular Wireless Networks
Many people use mobile stations, such as cell phones and personal digital assistants (PDAs), to communicate with cellular wireless networks. These mobile stations and networks typically communicate with each other over a radio frequency (RF) air interface according to a wireless protocol such as Code Division Multiple Access (CDMA), perhaps in conformance with one or more industry specifications such as IS-95 and IS-2000. Wireless networks that operate according to these specifications are often referred to as “1×RTT networks” (or “1× networks” for short), which stands for “Single Carrier Radio Transmission Technology.” Another protocol that may be used is known as Evolution Data Optimized (EV-DO), perhaps in conformance with one or more industry specifications such as IS-856, Release 0 and IS-856, Revision A. Other protocols may be used as well, such as Long-term Evolution (LTE), Global System for Mobile Communications (GSM), Time Division Multiple Access (TDMA), WiMax, and/or any others.
These networks typically provide services such as voice, Short Message Service (SMS) messaging, and packet-data communication, among others, and typically include a plurality of base stations, each of which provide one or more coverage areas, such as cells and sectors. When a mobile station is positioned in one of these coverage areas, the mobile station can communicate over the air interface with the base station, and in turn over one or more circuit-switched and/or packet-switched signaling and/or transport networks to which the base station provides access.
The base stations for these networks are typically not associated with any subscriber or small group of subscribers in particular; rather, they are placed in publicly-accessible locations and are used by the service provider's customers generally. These base stations collectively blanket cities, rural areas, etc. with coverage; as such, they are referred to generally and herein as “macro (or macro network) base stations” and the network they collectively form—or to which they collectively belong—is referred to generally and herein as the “macro network.”
Mobile stations and macro base stations conduct communication sessions (e.g., voice calls and data sessions) over frequencies known as carriers, each of which may actually be a pair of frequencies, with the base station transmitting to the mobile station on one of the frequencies, and the mobile station transmitting to the base station on the other. Furthermore, using a sector as an example of a coverage area, macro base stations may provide service in a given sector on one carrier, or on more than one. For example, in a CDMA wireless network, each cell employs one or more carrier frequencies, and each sector is distinguished from adjacent physical sectors by a pseudo-random number offset (PN offset). Further, each sector can concurrently communicate on multiple different channels, distinguished by Walsh codes. When a mobile station operates in a given sector, communications between the mobile station and the macro base station of the sector are carried on a given frequency and are encoded by the sector's PN offset and a given Walsh code.
According to industry standards IS-2000 and IS-95, a mobile station can communicate with a number of “active” sectors concurrently, which collectively make up the mobile station's “active set”. Depending on the system, the number of active sectors can be up to six (currently). The mobile station maintains in a memory a list of the sectors in its active set. In practice, the mobile station receives largely the same signal from each of the sectors of its active set and, on a frame-by-frame basis, selects the best signal to use.
2. Low-Cost Internet Base Stations (LCIBs)
Many macro network subscribers, including private consumers and small businesses, among others, in addition to having wireless service for their mobile station (or mobile stations), also have high-speed (a.k.a. “broadband”) Internet access through another communication channel, which may be cable-modem service, digital-subscriber-line (DSL) service, satellite-based Internet service, and/or some other option.
In an exemplary arrangement, a user may have a cable modem connected (a) via coaxial cable to a cable provider's network and (b) via Ethernet cable to a wireless (e.g., IEEE 802.11 (Wi-Fi)) router. That router may include one or more Ethernet ports to which computers or other devices may be connected, and may also include wireless-access-point functionality, providing a Wi-Fi packet-data interface to, as examples, laptop computers, digital video recorders (DVRs), appliances, and/or any other computing devices or their wireless network adapters.
To address gaps in macro network coverage (e.g., in buildings) and for other reasons, macro network service providers offer consumers devices referred to herein as Low-Cost Internet Base Stations (LCIBs), which may also be referred to as femtocells (femto base stations, femto base transceiver stations (BTSs)), picocells (pico base stations, pico BTSs), microcells (micro base stations, micro BTSs), small cells, and by other names. Note that the aforementioned terms that end in “cell” may also be generally and herein used interchangeably to refer to the coverage area provided by the respective device. Note also that “low-cost” is not used herein as a limiting term; that is, devices of any cost may be categorized as LCIBs, though most LCIBs typically will be less expensive on average than most macro network base stations.
A typical LCIB may be approximately the size of a desktop phone or Wi-Fi access point, and is essentially a low-power, low-capacity version of a macro base station. Thus, a typical LCIB will use a normal power outlet, perhaps with a transformer providing a DC power supply. The LCIB may have a wired or wireless connection with the user's router, and would thus have connectivity to the Internet and/or one or more other packet-data networks via the user's broadband connection. An LCIB may establish a virtual private network (VPN) connection over the Internet with an entity (e.g., a VPN terminator) on the wireless-service (macro network) provider's core network, and thereby be able to securely communicate with the VPN terminator and other entities on that core network and beyond.
The LCIB also has a wireless communication (e.g., CDMA, EV-DO, LTE) interface that is compatible with the user's mobile station(s), such that the LCIB may act as a micro base station, providing coverage on the wireless-service provider's network via the user's Internet connection. Usually, an LCIB will provide service on a single RF carrier (or on a single carrier per technology, where multiple technologies are supported), and also transmit what is known as a pilot beacon, which includes administrative messages and parameters that mobile stations can use to connect with the LCIB. And LCIBs typically include a satellite-based positioning system (SPS) receiver (e.g., a Global Positioning System (GPS) receiver) for use in receiving and decoding SPS signals, for use in determination of location, as well as for use in synchronizing operations with other LCIBs and with the macro network, based on timing information embedded in SPS signals. Typically, LCIBs have fairly comprehensive auto-configuration capabilities, such that they are largely “plug-and-play” to the user.